As the use of integrated circuits becomes more pervasive, the geometries of individual circuits continue to shrink. Generally speaking, the lithographic process, which involves patterning a photoresist material and subsequently anisotropically etching underlying layers, determines the size of the smallest features which can be created in an integrated circuit. However, designers have continually sought techniques which will produce features or openings which have dimensions that are less than what may be achieved by conventional lithography.
One of the most fundamental features of a MOSFET (metal oxide semiconductor field effect transistor) is the gate. Generally speaking, circuits with smaller gates operate more quickly, and contain more transistors.